Boob-spuing



UNTED STATES PATENT FFCE.

THOMAS J. MAYALL, OF-ROXBURY, MASSACHUSETTS.

DGR-SPRING.

Specification of Letters Patent No. 22,441, dated. December 28, 1858.

.To all whom it may concern:

Be it known that IfTi-Ioiuas J. MAYALL, of Roxbury, in the county of Norfolk and State of Massachusetts, have invented a new and Improved Door-Spring, of which the following is a full, clear, and exact description7 reference being had to the accompanying drawings, in which- Figure l is a view of a door with my improved spring. attached. Fig. 2 a section through a portion of the spring and its attachment.

To enable others skilled in the art to manufacture and use my springs l will proceed to describe their construction and operation.

ln the said drawings A- is the door, B the spring which is a cylinder of india rubber formed of successive layers of vulcanized rubber, or it may be manufactured solid and vulcanized in the form which it is ultimately t0 have. The ends of the spring are secured to sockets C and D one of which is attached to the jamb and the other to the door. The lower socket D is allowed to turn freely upon the bracket E which supports it, and has upon its lower edge a number of notches into which tits the spring catch g F ig. 2, which is pivoted to the bracket E.

By turning the socket D more or less and locking it by the catch g the spring may be made to close the door with more or less force, and by turning the socket in the opposite direction the spring may be caused to hold the door open. The spring operated by torsion, is ot' small cost, and not liable to wear out or breakt What I claim as my invention and desire to secure by Letters Patent as a new article of manufacture is- The within described india rubber, torsion, door spring operating as described.

THS. J. MAYALL. lWitnesses Trios. R. RoAoH, P. E. TESGHEMAGHER. 

